Seems very much like the opposite to me, even Nvidia's "Founder's Edition" went to an open design in its latest iteration. Only AMD reference cards seem to still be blowers, AIO designs are pretty much all open.
Now that I look, it does seem like a lot of them are open air cards. I have a mini ITX case, so I only ever look at blower cards since I don't really have the airflow to carry the GPU heat out.